funny wiring connector

rsporsche

rsporsche

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okay guys, i know we have talked about reverse light wiring before. i've got 2 sets of blue / white + green / white wires. i will remind you that my car was originally a 2800 csa. any thoughts?

1st set which look original, since they are the older type of wire - see pic below, these wires are taped together with the window wiring - all similar wire type. this is NOT very far away from the hole through the tranny tunnel that i have spoken about. i am about to start untaping the interior wiring to find out if they still go somewhere.

1783619803692.png


2nd - these wires are in a funny circular 5 pin connector - so far i haven't found the other side of this connector - might be attached to the reverse light switch?. i assume this was done during the tranny swap. the other wires in this connector are a bit confusing. the loop of brown wire and then the brown / white wire - it has a female spade on it. the only brown / white wire i have seen on the wiring diagram goes to a remote thermometer transmitter <i presume this is the water temp sensor in the thermostat housing that goes to the temp gauge in the multi gauge>

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no idea Chris, i haven't found the other end of the connector or switch. curiosity, wouldn't the switch be on the tranny? this plug is under the dash - i have 2 wires going thru the dash and hanging down with the speedo cable (haven't gone under the car recently). haven't found out if these are the same wires that go thru the firewall yet - just looking at the low hanging fruit first so i can route it where it needs to go - to heater / ac, console, etc.
 
I engaged Gemini on the picture of your two lose wires:

Based on the classic BMW wiring scheme (and looking right at the transmission tunnel area near the shift boot), those two snipped wires protruding from the harness are for your reverse light switch (back-up lights) on the gearbox.

Wire Breakdown​

  • Green with White stripe (GN/WS): This is the fused $12\text{V}$ power feed coming from the ignition circuit (hot when the key is in the "Run" position).
  • Blue with White stripe (BL/WS): This is the return wire that runs back to the rear tail light housings to illuminate the reverse light bulbs.

⚙️ How to Connect Them​

When you put a manual gearbox (like a Getrag 265) into the car, these two wires need to pass through the transmission tunnel boot/grommet down to the mechanical switch located on the top/side of the transmission casing.

Because the switch is a simple completion circuit, orientation doesn't matter—you just connect one wire to each spade terminal on the transmission's reverse switch. When you shift into reverse, the internal pin bridges the two wires, sending power from the green/white wire back to the bulbs via the blue/white wire.
 
rsporsche said:
no idea Chris, i haven't found the other end of the connector or switch. curiosity, wouldn't the switch be on the tranny? this plug is under the dash - i have 2 wires going thru the dash and hanging down with the speedo cable (haven't gone under the car recently). haven't found out if these are the same wires that go thru the firewall yet - just looking at the low hanging fruit first so i can route it where it needs to go - to heater / ac, console, etc.
Click to expand...
Yes connector is under dash.
 
Correct but are connected to separate spade connectors that plug into the switch. As discussed previously… mine went through transmission tunnel shifter hole.
 
my wires got sheared off when i was removing the tar insulation ... didn't know they were there. i am going to remove all of the tape on the harness inside the car and find out which blue / white + green / white wires are actually being used ... since i have 2 different sets in 2 different places.
 
I have that exact same grey connector, under the dash, just researched extensively and connected it. On my car, it is the reverse light, connects to a separate part of the harness that goes to that switch via a hole in the pedal box area. My car is a '73 CSa converted to manual
 
okay, i have removed all of the tape on the harness inside the car (well almost, i have a little bit to undo around the fuse box). so in regard to the green / white + blue / white wires.

i will start with the wires running from under the console.
1. both blue / white + green / white wires go in front of the driver seat to the left side of the car.

2. when reaching the side of the car, the blue / white wire turns toward the rear of the car and goes to the reverse lights on the rear light cluster. there is NO blue / white wire between the firewall and the drivers seat (within the main harness)

3. the green white wire turns toward the firewall <goes to fuse 7 in the fusebox>. there is NO green / white wire between the drivers seat and the rear of the car.

this agrees with the wiring diagram. that being said, i haven't figured out what is going on with the wires going through the firewall and the 'funny' 5 pin connector. for the time being, i am going to splice a piece of blue wire and green wire to penetrate the tranny tunnel with a new grommet.
 
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